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E Brainis

Publications and source records attributed to E Brainis.

4 recordsLinked to original sources
PubMed2005

Experimental error filtration for quantum communication over highly noisy channels.

Error filtration is a method for encoding the quantum state of a single particle into a higher dimensional Hilbert space in such a way that it becomes less sensitive to noise. We have realized a fiber optics demonstration of this method and illustrated its potentialities by carrying out the optical part of a quantum key distribution scheme over a line whose phase noise is too high for a standard implementation of BB84 to be secure. By filtering out the noise, a bit error rate of 15.3% +/- 0.1%, which is beyond the security limit, can be reduced to 10.6% +/- 0.1%, thereby guaranteeing the cryptographic security.

Journal Article↗
PubMed2005

Vector modulation instability induced by vacuum fluctuations in highly birefringent fibers in the anomalous-dispersion regime.

We report a detailed experimental study of vector modulation instability in highly birefringent optical fibers in the anomalous-dispersion regime. We prove that the observed instability is mainly induced by vacuum fluctuations. The detuning of the spectral peaks agrees with linear perturbation analysis. The exact shape of the spectrum is well reproduced by numerical integration of stochastic nonlinear Schrödinger equations describing quantum propagation.

Journal Article↗
PubMed2005

Provably secure experimental quantum bit-string generation.

Coin tossing is a cryptographic task in which two parties who do not trust each other aim to generate a common random bit. Using classical communication this is impossible, but nontrivial coin tossing is possible using quantum communication. Here we consider the case when the parties do not want to toss a single coin, but many. This is called bit-string generation. We report the experimental generation of strings of coins which are provably more random than achievable using classical communication. The experiment is based on the "plug and play" scheme developed for quantum cryptography, and therefore well suited for long distance quantum communication.

Journal Article↗